Middle cerebral artery syndromes

M1 segment

• Contralateral hemiplegia
• Contralateral gaze palsy, ipsilateral gaze preference
• Contralateral hemisensory loss
• Contralateral spatial neglect. Profound neglect in nondominant hemisphere lesions
• Contralateral hemianopsia
• Global aphasia if dominant hemisphere
• Anosognosia and anosodiaphoria, confusion, whispering voice, inability to maintain eye closure, constructional apraxia may also exist at varying degrees in nondominant hemisphere lesions

M2 segment, superior division

• Contralateral arm and face weakness
• Contralateral gaze palsy
• Varying degree of contralateral cortical type sensory loss in arm and face
• Varying degree of right spatial neglect may exist in dominant hemisphere lesions. Profound left spatial neglect in nondominant hemisphere lesions
• Broca’s (nonfluent) aphasia if dominant hemisphere

M2 segment, inferior division

• Usually mild or no motor deficit
• Varying degree of contralateral cortical type sensory loss in arm and face
• Profound left spatial neglect if nondominant hemisphere
• Wernicke’s (fluent) aphasia if dominant hemisphere
• Contralateral superior quadrantanopia or hemianopia
• There may be ipsilateral gaze preference at onset

Deep, penetrating (lateral lenticulostriate) branches from M1 segment

• Contralateral hemiplegia
• Contralateral hemisensory loss
• Transcortical motor or sensory aphasia

Orbitofrontal artery (superior division branch)

• Frontal syndrome with disinhibition and socially inappropriate behaviour
• Compulsive joking (Witzelsucht of Oppenheim)
• Continuous laughing (moria of Jastrowitz)
• Contralateral grasping
• Contralateral conjugate deviation of the eyes

Precentral sulcus artery (superior division branch)

• Contralateral arm weakness
• Contralateral limb-kinetic apraxia
• Motor impersistence if nondominant hemisphere
• Apraxia of eyelid closure
• Contralateral hemineglect

Prefrontal artery (superior division branch)

• No motor or sensory deficit
• Cognitive and behavioral deficits including perseveration, loss of planning ability, imitation and utilization behavior, poor abstraction, abulia and apathy
• Prefrontal syndrome of Luria - inability to follow sequential instructions, disinhibition and impulsive behavior
• Transcortical motor aphasia may be present

Central sulcus artery (superior division branch)

• Contralateral hemiparesis if proximal occlusion or arm weakness if more distal occlusion
• Contralateral hemisensory loss if proximal occlusion or arm sensory loss if more distal occlusion
• Bilateral damage to the low primary motor cortex may result in the Foix-Chavany-Marie syndrome characterised by severe dysarthria, loss of voluntary control of facial, masticatory, lingual and pharyngeal muscles with preserved reflexive and automatic functions

Postcentral sulcus artery

• Conduction aphasia (damage to arcuate fasciculus) if on dominant hemisphere
• Contralateral hemisensory disturbances, including allodynia and spontaneous pain resembling thalamic infarction
• Rarely, cheiro-oral syndrome (hemisensory loss of contralateral mouth and fingers) may be observed
• Contralateral hemineglect with possible asymbolia (inability to recognise or attach meaning) for pain
• Minimal motor weakness in face and arm may be observed
• Ataxia without hemisensory loss may be observed
• Contralateral visuospatial hemineglect, especially in nondominant hemisphere lesions

Temporal arteries (inferior division branches)

(temporooccipital, posterior temporal and middle temporal arteries)

• Wernicke’s aphasia if dominant hemisphere
• Alexia with agraphia if dominant hemisphere
• Contralateral visual hemineglect if nondominant hemisphere
• Micropsia if nondominant hemisphere
• Amusia - defect in processing pitch, musical memory and identification of tone and melody. Typically results from nondominant hemisphere lesion
• Constructional apraxia if nondominant hemisphere
• Confusion, hallucinations, restlessness and distractability may be observed, probably resulting from disruption of limbic structures, most often of the nondominant hemisphere
• Acute agitated delirium has been described in infarcts of the nondominant middle temporal gyrus

Posterior parietal artery (may originate from upper or lower division)

• Contralateral weakness in arm and face
• Contralateral cortical sensory loss in arm and face
• Contralateral hemiextinction on bilateral sensory stimulation
• Ideomotor apraxia
• Wernicke’s aphasia or anomic aphasia if dominant hemisphere
• Constructional dyspraxia if nondominant hemisphere

Angular artery (may originate from upper or lower division)

• Alexia with agraphia
• Gerstmann syndrome: agraphia, acalculia, finger agnosia/anomia, left-right disorientation if dominant hemisphere, often resulting from damage to the inferior parietal lobule.
• Bilateral infarcts can produce Bálint’s syndrome: optic apraxia (loss of voluntary control of eye movements), optic ataxia, asimultagnosia (inability to direct a panoramic view) and visual inattention.